Turbine exhaust cylinder strut strip for shock induced oscillation control

Patent metadata

Field	Value
Publication number	US-2016376929-A1
Application number	US-201514753384-A
Country	US
Kind code	A1
Filing date	Jun 29, 2015
Priority date	Jun 29, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

An arrangement to control vibrations in a gas turbine exhaust diffuser is provided. The arrangement includes a protrusion coupled to a turbine exhaust cylinder strut for controlling shock induced oscillations in a gas turbine diffuser. The controlled shock induced oscillations minimize pressure fluctuations in the gas turbine exhaust diffuser such that an unsteadiness of the fluid flow surrounding the turbine exhaust cylinder strut is reduced. A method to fluid flow induced vibrations in a gas turbine diffuser is also provided.

First claim

What is claimed is:

1 . An arrangement to control vibrations in a gas turbine exhaust diffuser ( 10 ), comprising:
a gas turbine exhaust diffuser ( 10 ), comprising:
a turbine exhaust manifold ( 30 ) connected to a turbine exhaust cylinder ( 20 ) establishing a fluid flow path, the fluid flow path bounded radially outward by an outer conical surface ( 65 ) and bounded radially inward by an inner conical surface ( 55 );
a turbine exhaust cylinder strut ( 190 , 195 )) arranged in the turbine exhaust cylinder ( 190 ) between the outer conical surface ( 65 ) and the inner conical surface ( 55 ); and
a protrusion ( 200 ) disposed on the turbine exhaust cylinder strut ( 190 , 195 ) for controlling shock induced oscillations in a gas turbine diffuser ( 10 ), wherein the controlled shock induced oscillations minimize pressure fluctuations in the gas turbine exhaust diffuser ( 10 ) such that an unsteadiness of the fluid flow surrounding the turbine exhaust cylinder strut ( 190 , 195 ) is reduced.

2 . The arrangement as claimed in claim 1 , wherein the protrusion ( 200 ) is disposed on a suction side ( 210 ) of a turbine exhaust cylinder strut airfoil ( 190 ).

3 . The arrangement as claimed in claim 2 , wherein the protrusion ( 200 ) is disposed on the suction side ( 210 ) of a leading edge ( 220 ) of a turbine exhaust cylinder strut airfoil ( 190 ).

4 . The arrangement as claimed in claim 1 ,
wherein the protrusion ( 200 ) is a rectangular strip ( 300 ) chamfered on a corner of the rectangular strip ( 300 ) creating an chamfered edge ( 350 ), and wherein the chamfered edge ( 350 ) faces the fluid flow from the leading edge ( 220 ) of the turbine exhaust cylinder strut airfoil ( 190 ).

5 . The arrangement as claimed in claim 4 , wherein a chamfer angle (A) measured from a top face ( 310 ) of the rectangular strip ( 300 ) to the chamfered edge ( 350 ) is less than 30 degrees.

6 . The arrangement as claimed in claim 4 , wherein the rectangular strip ( 300 ) is attached to the turbine exhaust cylinder strut ( 190 , 195 ) by an attachment process selected from the group consisting of welding, bolting, and riveting.

7 . The arrangement as claimed in claim 6 ,
wherein a front attachment zone ( 360 ) is disposed on a front face ( 330 ) of the rectangular strip ( 300 ) such that an angle of an edge of the attachment zone with respect to the top face ( 310 ) is the chamfer angle (A), and wherein an edge ( 380 ) of the front attachment zone ( 360 ) and the chamfered edge ( 350 ) of the rectangular strip ( 300 ) form a continuous ramped front edge ( 350 , 380 ).

8 . The arrangement as claimed in claim 6 ,
wherein an aft attachment zone ( 370 ) is disposed on a back face ( 340 ) of the rectangular strip ( 300 ), and wherein the aft attachment zone ( 370 ) does not extend to the top face ( 310 ) of the rectangular strip ( 300 ) such that a backward facing step is formed above the aft attachment zone ( 370 ) fixing a location of fluid flow separation.

9 . The arrangement as claimed in claim 4 ,
wherein a height (h) of the rectangular strip ( 300 ) from a hub ( 400 ) of the turbine exhaust cylinder strut ( 190 , 195 ) is between and 40% and 70% of the span of the turbine exhaust cylinder strut ( 190 , 195 ).

10 . The arrangement as claimed in claim 4 , wherein a thickness (t) of the rectangular strip ( 300 ) is in a range of 3% to 6% of strut maximum thickness.

11 . The arrangement as claimed in claim 1 , wherein a material of the protrusion ( 200 ) is the same as a material of the turbine exhaust cylinder strut ( 190 , 195 ).

12 . The arrangement as claimed in claim 3 , wherein a distance from the leading edge of the turbine exhaust cylinder strut ( 190 , 195 ) to a leading edge of the protrusion on the suction side ( 210 ) is in a range from 7.5% to 12% of the strut chord length.

13 . A method for controlling fluid flow induced vibrations in a gas turbine diffuser ( 10 ), comprising:
disposing a protrusion ( 200 ) on a turbine exhaust cylinder strut ( 190 , 195 ) of the gas turbine exhaust diffuser ( 10 ); coupling the protrusion ( 200 ) to the turbine exhaust cylinder strut ( 190 , 195 ), wherein the protrusion ( 200 ) controls shock induced oscillations which minimizes pressure fluctuations in the gas turbine exhaust diffuser ( 10 ) such that an unsteadiness of fluid flow surrounding the turbine exhaust cylinder strut ( 190 , 195 ) is reduced.

14 . The method as claimed in claim 13 , wherein the disposing includes positioning the protrusion ( 200 ) on the suction side ( 210 ) of the leading edge ( 220 ) of a turbine exhaust cylinder strut airfoil ( 190 , 195 ).

15 . The method as claimed in claim 13 , wherein the coupling includes welding the ( 200 ) protrusion to a surface of a turbine exhaust cylinder strut ( 190 , 195 ).

16 . The method as claimed in claim 14 , wherein a distance from the leading edge of the turbine exhaust cylinder strut ( 190 , 195 ) to a leading edge of the protrusion ( 200 ) on the suction side ( 210 ) is in a range from 7.5% to 12% of the strut chord length.

17 . The method as claimed in claim 13 , wherein the protrusion ( 200 ) is a rectangular strip ( 300 ) chamfered on a corner of the rectangular strip ( 300 ) creating an chamfered edge ( 350 ), wherein the chamfered edge ( 350 ) faces the fluid flow from the leading edge of the turbine exhaust cylinder strut airfoil ( 190 , 195 ).

18 . The method as claimed in claim 17 , wherein a chamfer angle (A) measured from a top face ( 310 ) of the rectangular strip ( 300 ) to the chamfered edge ( 350 ) is less than 30 degrees.

19 . The method as claimed in claim 15 ,
wherein the welding includes disposing a front weld bead ( 360 ) on a front face ( 330 ) of the rectangular strip ( 300 ) such that an angle of an edge ( 380 ) of the weld bead with respect to the top face ( 310 ) is the chamfer angle (A), and wherein the edge ( 380 ) of the weld bead and the chamfered edge ( 350 ) of the rectangular strip ( 300 ) form a continuous ramped front edge.

20 . The method as claimed in claim 11 ,
wherein the welding includes disposing an aft weld bead ( 370 ) on a back face ( 340 ) of the rectangular strip ( 300 ), and wherein the aft weld bead ( 370 ) does not extend to the top face ( 310 ) of the rectangular strip ( 300 ) such that a backward facing step is formed above the aft weld bead ( 370 ) fixing a location of fluid flow separation.

Assignees

• Siemens Energy Inc

Inventors

• Akturk Ali
• Rodriguez Jose L
• Wasdell David L
• Orosa John A
• Montgomery Matthew D

Classifications

• F15D1/0025

  using passive means, i.e. without external energy supply · CPC title

• F05D2260/964

  counteracting thermoacoustic noise · CPC title

• F05D2240/121

  related to the leading edge of a stator vane · CPC title

• F01D25/162

  Bearing supports · CPC title

• F01D25/30 Primary

  Exhaust heads, chambers, or the like · CPC title